A new style of contour parallel tool path, which is called uneven offset tool path, for free form pockets machining is developed in this paper.

The algorithm had been compiled in the developed RPM data processing software. Using the new algorithm, the stability is improved and the OFFSET tool path can be generated in the RPM process.

Initialization of tool offset is a very important step in the operation of NC-lathe, which influences directly operation of machine and precision of parts processing.